Abstract
Inattentional blindness, where large elements of a scene are undetected by subjects concentrating on other tasks, has been studied using methods requiring naive subjects and a single “critical” trial. Is there a technique which can use usual psychophysical methods and would the results confirm standard attentional explanations? We used a miscuing design where, on some trials, 3 subjects were cued to locations other than where the change occurred. Orientation increment thresholds were found using a temporal same-different task. Stimuli were rings of 2,3,4 or 6 D6 elements: at 0.97 eccentricity, of uniform or mixed orientations, presented for 100 msec with a 900 msec ISI. Cues presented near fixation point for 100 msec before the 1st stimulus were correct in 60%, incorrect in 20% and absent in 20% of trials. Uniform pattern thresholds remained below 9 with no evidence of a set size or cueing effect. The situation was very different for mixed patterns. There was a set size effect and a striking effect of cueing, becoming more evident as the number of patches increased. Thresholds for 2 element patterns for the three cue conditions were all 10, while for 6 element patterns correctly cued (attended) thresholds were 20, uncued (change blind) thresholds were 29 and miscued (inattentional) thresholds were 39 . The deficits in performance for inattentional trials provide an even greater challenge than that of change blindness for standard spatial attention theories. This study suggests that standard psychophysical uncertainty effects, change blindness and inattentional blindness are unified as phenomena which may all be studied using the same type of simple multi-element patterns and theoretical framework. They vary only in whether there is one or more presentations, pattern elements uniform or mixed, subjects naive or not, and relevant element cued, uncued or miscued. The last is the defining characteristic of inattentional blindness.
Supported by EPSRC GR/R56174, Wellcome Trust Vacation Scholorship, and Nuffield NUF-URB02 grants.